1. Field of the Invention
The present invention relates to a mobile communication device. More particularly, the present invention relates to a mobile communication device having a multi-band antenna.
2. Description of the Related Art
With the vigorous development of mobile communication industries, products for mobile communication devices have become very diverse, with mobile phones being the most popular among all these products. Nowadays, the essential requirements of a mobile phone include not only a communication function but also a multimedia application and transmission function. For example, a user may utilize an internet access function of a mobile phone to obtain real-time information, take care of important documents, or enjoy video/audio entertainment. Most of the services provided by a mobile phone are achieved by wireless communication transmission. Therefore, an antenna is an important key element in the design of a multimedia mobile phone.
In order to achieve a variety of different wireless applications, it has become a trend to develop a multi-band antenna for a mobile phone. This means that the antenna for the mobile phone should be capable of performing multi-band operations at the same time. Generally, most mobile phone antennas are designed as inverted-F antennas commonly implemented to achieve multi-band or wide-band operations by utilizing multiple resonant paths to generate multiple resonant modes. For example, Taiwan Patent No. 1227576 (Dual-band inverted-F antenna with a shorted parasitic element) discloses an antenna to achieve multi-band operations by utilizing multiple resonant paths to generate multiple resonant modes. However, the operating bandwidth of the antenna is still very limited and cannot meet 8-band operations required by current wireless communication technology such as long term evolution (LTE) and wireless wide area network (WWAN). The 8-band operations include 3 low-frequency bands for the LTE700/GSM850/900 (698˜960 MHz) operations and 5 high-frequency bands for the GSM1800/1900/UMTS/LTE2300/LTE2500 (1710˜2690 MHz) operations. Further, if there is a need to utilize more resonant paths to achieve the wide-band or multi-band operations, the physical size of the antenna would be too big to fit in a modern mobile phone.
Therefore, it is necessary to provide a mobile communication device and antenna thereof to overcome the deficiency encountered by the prior art techniques.